1. Field of the Invention
The present invention relates to an apparatus converting microscopic thermal energy into macroscopic mechanical energy using a temperature difference.
2. Description of the Related Art
A micropump using electro-osmosis is relatively simple in structure and easy to mount to a micro-channel. Therefore, the micropump is used in such fields as μTAS (Micro-Total Analysis System).
In these circumstances, attention has been recently paid to a micropump using Induced-Charge Electro Osmosis (ICEO) for the reason that the micropump can increase a flow rate of liquid, and suppress chemical reactions between electrodes and the liquid since the micropump can be driven by AC.
U.S. Pat. No. 7,081,189 discusses a micro-mixer that serves as a mixer (mixing device) using ICEO and a pump (liquid conveyance device), and that uses vortex produced by ICEO flow around a cylindrical metallic post, and a micropump using the ICEO flows.
Meanwhile, L. Callegaro and M. Pisani, Appl. Phys. Lett. 89, 034105 (2006) discusses that a temperature difference between two impedances causes electric energy deriving from thermal noise to transfer between the two impedances.
Although the mixer and the pump, discussed in the U.S. Pat. No. 7,081,189, is expected to be used in the future, each of the mixer and the pump needs a power supply applying an electric field to the cylindrical metallic post to produce the ICEO flows.
A battery, a DC power supply in place of the battery and an AC power supply is generally considered as the power supply. If it is possible to use energy different in properties from these power supplies by converting to electric energy, it is highly probable to extend the use of a fluid element.
Furthermore, if energy conversion can be made using the fluid element, the technique has the potentiality as a new energy conversion method.
On the other hand, L. Callegaro and M. Pisani, Appl. Phys. Lett. 89, 034105 (2006) fails to specifically discuss how to extract electric energy although the transfer of the electric energy between the impedances is described.